In both humans and animals, vitamin A (VA) and beta-carotene (BC), the major dietary precursor of VA, are important for immunocompetence. Deficiency depresses cell-mediated immunity and augments susceptibility to death from infectious diseases in the general population and in patients with AIDS, VA deficiency is associated with greater risk of death. Based upon studies from the PI and others that BC increases CD4 cell count, this project is designed to quantify the prevalence of VA deficiency and malabsorption and conduct a 4 month trial of BC.